Sandvik Mining and Construction Oy

Jyrki Nissinen

Mika Oksman

Ossi Kahra

Harri Moilanen

Juhani Laine

Ossi Grohn

A hydraulic percussion device and method of controlling a working cycle of a percussion piston is provided. A rock breaking machine includes a percussion device provided with a reciprocating piston executing a working cycle. The operation is controlled by means of a control unit generating control signals for independently operable feed and discharge valves of a hydraulic system. The position of the piston is detected by a sensing device.

Percussion device and method for controlling the same

A hydraulic breaking hammer and method of supporting a percussion piston is provided. The breaking hammer includes a percussion device provided with a reciprocating piston. The piston is supported on a frame at its end portions by a first piston bearing element and a second piston bearing element. The second piston bearing element includes a collar sealing element facing towards a working collar of the piston. The piston bearing elements are easily mountable and dismountable separate components.

Breaking hammer and method of supporting percussion piston

A seal of a tool of a breaking hammer, a sealing arrangement, a breaking hammer and a method of sealing a tool of breaking hammer is provided. The seal is a sealing ring having an outer periphery provided with several projecting elements, which are slanted. The projecting elements generate torque in the sealing ring when being pushed in a transverse direction during use of the breaking hammer. Thus, the sealing ring may rotate relative to the tool.

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Tampere, Finland

Jyrki Nissinen